Building on Caleb's point — the relationship-minded crowd clusters somewhere specific.
The tell with serious dating apps is usually how the account handles a direct question.
The thing I look at first with serious dating apps is whether the cancellation flow on serious dating apps actually works.
The honest answer on serious dating apps is that people looking for the same thing is the whole game.
If if the privacy settings is configurable at all — worth checking before you commit to serious dating apps isn't there, I don't bother with serious dating apps at all.